An invasive pest that kills oak trees continues to spread through the Willamette Valley between Portland and Salem.
Oregon officials completed a two-year study this summer that found the Mediterranean oak borer beetle across the valley in Clackamas, Marion, Multnomah, Polk, Washington, and Yamhill counties. Officials announced the findings this month.
“We’re not seeing a huge escalation in how many we are finding on the landscape, but it will continue to spread into other oak areas, and we want to know where those areas are,” said Christine Buhl, an entomologist with the Oregon Department of Forestry…